which differ from the previous prediction (see Table.).
Two factors had a decisive influence on the above relations.
One is kinematic factor. The phase space for \(B_{c}\)  \({\rightarrow }\) 
\(BP\)  decay is larger than that for \(B_{c}\)  \({\rightarrow }\)  \(BV\) 
decay, besides the orbital angular momentum
\(L_{BP}\)  \(<\)  \(L_{BV}\) .
The other is the form factor \(F_{1}^{B_{c}{\rightarrow }B}(q^{2})\) .
For example, in the previous work [1]},
the \(F_{1}^{B_{c}{\rightarrow }B}(q^{2})\)  goes up along with
the growth of \(q^{2}\) ,
while in this paper, the shape line of
\(F_{1}^{B_{c}{\rightarrow }B}(q^{2})\)  goes down in large
\(q^{2}\)  region.
The hierarchy between the branching ratios for
\(B_{c}\)  \({\rightarrow }\)  \(BP\)  and \(B_{c}\)  \({\rightarrow }\)  \(BV\) 
decays can be serve as a standard to distinguish
different approach, to check the practicality of
the pQCD approach.
